Stropping machine



Dec. 4 1923. I

. R. P. CUMMINGS STROPPING' MACHINE Filed Feb. '27

In rental:

IIIIIIII! "I'll" Patented Dec. 4, 1923 UNI ED sre'rss Mimi RALPH P.CUMMINGS, or soccer: ronrnann, name.-

srnorrmonncnmn Application filed February 27, 1922. Serial n 'aaavor.

To all whom it may concern:

Be it known that I, RALPH P. CUMMINGS, a citizen of the United States,residing at South Portland, in the county of Cumberland andStateofMaine, have invented new and useful Improvements in Stropping Machines,of which the following is a specification. r I

My invention relates to that class of machines into which so calledsafety razor blade maybe inserted and by a movement to and fro over thesurface of a strop whet or sharpen same until a keen edge is produced. I

In my mechanism the-blade is so presented to the surface of the strop asto get a whet ting action partly cross-wise and partly length-wise ofthe cutting beveled edge. I have demonstrated that I can produce 'akeener cutting blade by this method;

By referring to the drawing accompanying this specificationthe designand principle of construction can be clearly seen. In 1, I show, inperspective, the assembled device, with the blade inserted in theholder. and outline ofstr'op in dot and dash lines;

Fig. 2 is a view, in perspective, of a part of' the blade holder,showing a bladepartly inserted in same; Fig. 3 is a plan View of thecompletemachine; Fig. 4 is a side view, taken from the side'on which isthe rack and pinion gear, and Fig. 5 is a sectional view taken on linemw, Fig. 3.

Similar numerals refer to similar parts throughout the several views.

Pivotally mounted on a base plate 1, and turning about screw pin 2, is aflat: bar 3 with upturned ends 42, 4, in holes 5, 5, in which, rotatesrod 6. On this rod 6 is riveted or otherwise secured a blade holder 7,in the bifurcated edge of which can be inserted a safety-razor blade inits own mounting, as seen at .8. The two outwardly projectingbifurcations,'or as I may term them, plates,

of which holder 7 is partly composed, are

seen at 7', and in assemblingthis holder, these plates are slightlysprung together,

thus tending to hold the blade, within itsmounting, with a slightfrictional grip. The angular actionor pull on the blade when the machineis in operation drives it up firmly against the collar 9, which preventsfurther end movement to the blade. Beads over edges of plates 7 7prevent the blade mount from pulling I out of the holder while thestrop. I

n5 7 the machine is sliding along the surface of. v V secured to the topother 3, i

directlybeneath the blade holder 7, two side that a very supple and.resilient'contact of p the blade with the strep may be obtained,

while at the same time a dependable support p is provided for both. Onthe over-hanging end of bar 3 is a vertical handle or post 12, foroperating the machine.

f Opposite the operating end of bar'3,'and mounted rigidly on rod .6, isa segmental gear 13, adapted to operate in-circular rack 14, cut onover-extending edge of base plate 1; While I have described this as onemethod of imparting rotary movement to rod 6,I do not confine myselfspecifically to this design, as any'praotical combination of cams "andlevers which will accomplish my purpose may be substituted.

.On both ends of the. base plate 1: are

fenders 15,,extending upwardly from the fioor of the plate and havingsecurely fixed in-each, rods" 16, which extend across. the 3 spacebetween sides 15, '15. At 17 is shown the extreme ends of the baseplate'bent upward to form friction guards. 'By reference to- Fig. 5 itwill be seen that the strop'1'8 does not have a perfectly free movement'be-.

tween rod 16 and guard 17, or ingother words there is a slighttendency'to retard the free and uninterrupted travel of the machine overthe strop, the .reason for providing which feature to be hereinaftermade clear. i

In Fig. 4 the position assumed by the blade, gear and other parts issuch as would take place by .the movement ofthebar 3 .to

central position, or on line y g Fig. 3.-

There are also seen in Fig. 3 the two extreme positions of the movableparts of mymachine. Parts shown in. full lines would move in thedirection of the arrow, shown in full lines; and contra-wise for dottedparts. The blade upon which the stropping has been completed may bedetached from the 7 machine by pulling out of the holder, length- ,12and pulls or pushes, depending on which end of the strop the machine maybe located. In Fig. 3 we will assume that the machine 7 has just reachedthe extreme right hand end of-the strop (holder shown in full lines). It

might appear at glance that a bacle ward pull (or to the left as seen indraw ing) of the handle would force the blade into the strop. Such,however,- is not the case; what happens is this The slightfrictionalresistance of the machine over the strop, where the latter passesbetween rod 16 and guard 17, and to which reference has heretofore beenmade, is suf'icient to hold the body of the machine on the strop whilepulling thepostor handle 12 from the position at A to the positionat B;It is, in other words, a slip. movement, and there is no tendencywhatever for the blade to become imbedded in the strop when reversingthe direction of movement. The slightest action'of post 12 startsgear 13into action with rack 14', and

' as the former is rigidly secured to shaft 6,

which is in turn secured to holder 7, the blade will start upward fromthe strop on the first movement of gear 13, and until it has taken anextreme opposite position'on the base plate, no movement of the machineforward can be made.

Thetension of theblade on the strop constitutes a stop to pull or pushthe machine backward or forward and is in. proportion tothe amount offorce applied to post 12 in a turning action around pivot pin 2. Asstated in the preamble, the'stropping is a combination of crosswise andlength-wise whetting of the blade on the strop. The

' blade is placed at an angle with the strop and without change of thisangle is drawn over the length of the strop. The other side,

on the reverse movement, is treated likewise. Then by removing the bladefromthe holder and IGlIlSQItiIlgltWlth theends reversed a cross whettingisobtained.

This accomplishes what draw and cross filing does to a piece ofsteelwhere the cross filing marks show up, the draw filing The action ofmy 1 will smooth them off. machine gives a better edge to the razor,polishes the bevel-by cross-whetting, taking out the minutest abrasions,and with the same length off-blade does not. require as wide a strop inoperation. v

Having thus described mylinvention, I claim: I

A stropping machine comprising a'base member-slidably mountedon a stropand having an arcuate rack thereon, frame pivotally mounted on said basemember and adapted to be swungthrougha part of the circumference of acircle, around a pivot, an oscillating member journalled in said frame,a'blade holder, adapted to hold the blade yieldin'gly, rigidly securedto said oscillating member, a pinion rigidly secured to said oscillatingmember and in mesh" with said rack on said base member, resilientsupporting members beneath and 'in' contact with the strop, and at aspaced distance from the cutting edge of the blade, fenders on the endsof the basemember to properly guide the machine along the length of thestrop, guards on the ends of the base member projecting upwardly forapplying a slight frictional resistance to the progress of the machinealong the surface of the strop, means for actuating the frame so as toplace the blade in proper relationto the direc--- RALPH P; CUMMINGS.

